Airflow Velocity Designing for Air Classifier of Manufactured Sand Based on CPFD Method

Airflow classification is the key technology for the dry separation of manufactured sand. To solve the problem of low separation accuracy and poor gradation grade, the classification process of manufactured sand under different inlet and outlet airflow velocities changes in the multi-air inlet classifier is simulated by using Barracuda based on Computational Particle Fluid Dynamics (CPFD) method. The influence of various airflow velocity in air inlets and outlet on the sand classification is analyzed. The optimal combination of airflow velocity that meets the design goals is obtained. The results show that the airflow velocity and location of the air inlet and outlet have a significant impact on medium-grained (0.15~1.18 mm) and fine-grained (0.075~0.3 mm) sand. Adjusting the airflow velocity at air inlet 2 and air outlet can most effectively change the overall sand separation effect, while 41 m/s (inlet 2) and 6 m/s (outlet) would be the best velocity combination.

Laboratory Tests to Optimize the Milking Machine Settings with Air Inlet Teat Cups for Sheep and Goats

Milking machine design and performance are directly related to the milkability of sheep and goats, with the aim of milking quickly, completely and gently. This leads to an increase in the milk yield with improved quality, and the maintenance of healthy udders. The aim of this study was to carry out laboratory tests to determine the optimal level of vacuum, pulsation rate and pulsation ratio of new milking machines in high and low milk lines for sheep and goats. This study was conducted at the Department of Research and Development, Siliconform, Germany. For this purpose, different levels of vacuum (32, 34, 36, 38 and 40 kPa), milk jet (2, 2.5, 3 and 4 mm), milk line (high line and low line) and pulsation ratio (50:50 and 60:40) were used. First minute water flow (1st WF/kg) was used as an indicator for assessing the best combination in the milking machine. In addition, the cyclic vacuum fluctuation was measured in the inner chamber of the teat cup during the 1st WF/kg with the aid of a Vacuscope device. Statistical analysis was conducted using the mixed procedure in SAS. Our results show that the vacuum level, the milk jet and the pulsation ratio had a significant influence (p < 0.05) on the 1st WF/kg in the two milking machines for goats and sheep. In conclusion, the ideal conditions for milking goats with air inlet teat cups in the milking machine are a vacuum level of 36–38 kPa (low line) and 38–40 kPa (high line), a pulsation rate of 90 cycles/min and a pulsation ratio of 60:40, while the ideal conditions in the sheep milking machines are a vacuum level of 35–36 kPa (low line) and 36–38 kPa (high line), a pulsation rate of 120 cycles/min and a pulsation ratio of 60:40 or 50:50.

Development of an integrated cooling system for motorcycle helmet by physical study of temperature variations and heat transfer

In Colombia, the most widely used means of transport today are motorcycles, which have become increasingly numerous, bearing in mind that they are subject to laws and regulations imposed by the country’s mobility, transit and transport agencies, the use of helmets is mandatory for drivers and passengers, safety measures are monitored, the hull must be certified and meet the required technical standards; whereas its role is to protect people in the event of accidents, regulations require that the helmet be completely closed to protect the entire head and chin; the design of the helmet allows air entry and there is no concentration of temperature inside, all this is done by implementing air inlet and outlet ducts, which circulate air when the motorcycle is in motion, unfortunately this does not happen due to the accumulation of temperature in the back of the helmet that makes the user feel tired and uncomfortable. This research proposes the development of a prototype portable cooling system for motorcycle helmets by the physical principle of heat transfer, by using Peltier cells, to have low production cost, optimal operation, and low energy consumption thanks to natural air flow.

Speed distribution in the exhaust diffuser of the air fan

A perfect connection between the column and the fan is that which ensures an air inlet in the fan, evenly distributed, over the entire surface of the suction mouth and an air outlet from the fan outlet made in a way that allows the full use of developed pressure. For both suction and exhaust, fans must be equipped with a device/diffuser. When the fan discharges freely into the atmosphere without any connection, a loss equivalent to 50% of the average dynamic pressure at the discharge port occurs. If the fan discharges into a speaker, the loss depends on its angle. At a peak angle of 30° corresponds to a loss of ≈ 25% of the average dynamic pressure in the discharge mouth, and to reduce air vortices the speakers must be built at an angle of inclination to vertical or horizontal between 12- 15°, in order to reduce the aerodynamic resistances. The paper will present the speed field distribution of an axial fan located on a circular duct, provided on the air discharge side with a diffuser with a length of 1.5 m, at an angle of inclination to the vertical or horizontal of 12°.

Analysis of Water-Cooled Intercooler Thermal Characteristics

With the incremental power of construction machinery diesel engines, the power performance of diesel engines and the pollutant emissions from the exhaust gas have imposed increasingly stringent requirements on the intake cooling system of diesel engines. This paper compared the j/f evaluation factors for fin unit bodies of water-cooled intercooler (including straight fins and rectangular misaligned fins) by means of CFD simulation, and found that the rectangular misaligned fins had an 8% advantage in comprehensive performance. With the rectangular staggered fin intercooler, it was found that under the same conditions, the cooling efficiency of the dual-pass water-cooled intercooler is higher than that of the single-pass water-cooled intercooler, and the uniformity factor of the temperature difference field of the dual-pass water-cooled intercooler is 1.5% higher than that of the latter. The accuracy of the overall simulation of the intercooler is verified by the field test. The dual-pass and single-pass water-cooled intercooler both can maintain heat balance under working conditions, and its average air inlet temperature is 10 °C lower than that of the original air-cooled intercooler, which provides support for further reducing the engine air inlet temperature. The results provide a theoretical basis for the performance improvement of water-cooled intercoolers.

Application of Limitation Periods to Continuous Infringements

Air Inlet Grilles for Passenger Cars

Numerical Investigation Into the Effect of Air Swirl on Non-Premixed Combustion

Endeavour is made to investigate the effect of swirled air on methane-air combustion in a Harwell combustor geometry. The inlet air swirl intensity on combustion characteristics such as temperature, pollutant formation, and flow dynamics is studied. The modeling of turbulent characteristics is performed with the standard K–ε model using ANSYS Fluent. Eddy dissipation model with one step reaction is used for modeling chemical reaction and P-I radiation model for radiation heat transfer. The swirl number is achieved in the range of 0.0 to 0.6, by varying the tangential velocity to the air inlet. With the increase in swirl intensity, the maximum flame temperature drops, and most of the flame formation shifts towards the inlet of the furnace. The change in the flow field is aided by the formation of recirculating bubbles. The swirl causes the flame to spread radially away from the axis, thereby increasing the heat transfer flux to the furnace wall. As a result, a significant reduction in the formation of NO pollutants is observed.

Evaluación de la Viabilidad Técnica para la Captación del Agua Atmosférica acorde a las Condiciones Climatológicas del Municipio de Facatativá / Evaluation of the Technical Viability for the Atmospheric Water Capture according to the Climatological Conditions of Facatativá, Colombia

The aim of this work was to determine the technical feasibility to obtain atmospheric water according to the weather conditions in Facatativá, Colombia. Atmospheric water capture is an alternative source for a population with limited access to water resources. This problem is especially serious for vulnerable communities that require the development of new sources of water supply. For the development of this work, three phases were considered: Climatological dataset related with relative humidity and temperature in Facatativá were obtained from the IDEAM Villa Inés Station for the period 2006 - 2016. With these data the maximum amount of condensable water per kilogram of air and operating ranges for the experimental setup were calculated. The second phase involved of an experimental setup consisting of a glass chamber connected to two Peltier cells. Saturated air was fed into the chamber. A 24 factorial design was carried out where the factors were the air inlet flow and the temperature. The humidity and temperature data of the outlet air were obtained by means of electronic sensors. Finally, the interpretation of data and results of the water obtained were used to calculate the efficiencies of the process. The results of this work demonstrate the technical feasibility of obtaining water from humid air and propose improvements for the establishment of future assemblies.